Non smokers can develop lung cancer through a variety of ways: 1) Exposure to second hand smoke (smoke that dos not pass through the filter) have an increased chance of developing cancer 2) Pollution like those coming from vehicles 3) Chemical exposure (ex. asbestos has been linked to the development of a lung malignancy called mesothelioma) 4) Radiation exposure

Absolutely! They can receive the second hand smoke if they're around a smoker. It's more harmful to the second hand smoker because there isn't a filter for all that smoke. But a smoker has a filter in their cigarette. And you don't need to smoke or be any smoke. You can get lung cancer from other things called carcinogens like Radon Gas, Virus' etc. However your risk of lung cancer is highly elevated when you smoke.